Screw conveyer.



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SCREW CQNVEYEB. v APPLICATION FILED OCT- I6, I915.

' Patentd Jan. 23, 1917.

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0. 0. ERF-URTH- SCREW CONVEYER. H APPLICATION FILEDOCT. 16. 19 15. 1,213,171, V

Patented Jan. 23, 1917.- 5 sums-sum 2 '0. o.- mum.-

v SCREW CONVEYERr APPLICATION FIL ED'OCT- 16,- I915- Patented Jan. 23, 1917.

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SCREW CONVEYER.

APPLICATION FILED OCT-16.1915- Patented Jan. 23,1917.

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SCREW CONVEYER. v APPLICATION HLEDOCT-I 16, 1915. I i I I 1,213,171. Patented Jan. 23,1917.

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OTTOMAR OSKAR ERFURTH, 0F TEUCHERN, GERMANY.

scnnw convnYER.

Specification of Letters Patent.

' Patented Jan. 23,1917.

Application filed October 16, 1915. Serial No. 56,254.

To all whom it may concern:

lie it known that I, OTTOMAR OSK'A'R Enrnn'rn, manufacturer, a SLlbJGCt of the King of Prussia, and resident of Teuchern,

in the Province of Saxony, Kingdom of Prussia, German Empire, and whose po'stofiice address is Gartenstrasse, Teuchern, lrussia, have invented new and useful Improvements in Screw Conveyers, of which the following is a specification.

Screw conveyers for the simultaneous conveyance and compression of liquid, pulpy, plastic or of granular and coarse solid masses generally, comprise a helical band of narrow rectangular or triangular cross section arranged around a cylindrical or a conical boss or spi1 dle. the worm being rotated within a cylindrical or conical housing. The circumference of the helical band is cylindrical throughout or rises conically. By the helical shape of the band the material charged in at one end is conveyed to the other end while being simultaneously subjected to compression or concentration as a consequence either of the conical taper of the passage toward the outlet or of the reduction of this passage due to the rise of the helical band toward the outlet or of the combination of both. In contradistinction to this known construction, this invention has the characteristic feature that-the helical band of the worm is not wound around a cylindrical or conical boss but around a hub or spindle, the circumference of which itself rises in the form of a helix, that is to say, each cross section of the boss is not circular, as in the case of a cylindrical or conical boss but is of spiral shape, that is to say, forms'a curve of gradually varying curvature in which the distance of all points increases from the root of the curve. By this shape of the boss the advantage is obtained that the compression of the material longitudinally advanced by the helical band takes place in a purely radial direction vertical to the direction in which the material is conveyed by the worm, at a uniformly increasing pressure and with the avoidance of all such axial counterpressures as usually occur when a conical' hub is employed.

The accompanying drawings illustrate by way of example in Figures 1, 2 and 3,the invention diagrammatically while Figs. 4 to 9 represent some instances of the manifold application of the invention.

'fills the sieve d only at the outlet.

juice passes into an annular trough e and In Fig. 1 a is the worm spindle which is journaled in a suitable manner and by means of any known drivingarrangement is maintained in continuous rotation. Secured to this shaft is the worm according to this invention, comprising the hub b and a helical band 0 wound thereon.

In Figs. 2 and 3 the helical band c-is omitted in order to show more clearly the helical shape of the hub.

As shown the hub b rises from the small radius r to the large radius R helically and stepwise so, however, that its circumference follows a helix as illustrated in Fig. 3. In all stages 1, 2, '3 and 1 of this spirally rising hub the end view or a cross section show the form of a spiral with constantly increasing radius. Therefore, if such a worm is rotated within a cylindrical housing d, for example, in the direction of the arrow shown in Fig. 1, it will be seen that the material charged in laterally of the. portion 1 and to be conveyed and compressed is advanced by the helical band 0 in the direction of the arrow while the spirally rising hub 12 exerts at the same time between the screw threads a gradually increasing pressure radially, that is to say, vertically to the conveying movement.

Figs. 1 and 5 show a constructional form adapted for the expression of juice from fruit. In this case the arrangement is vertical and the worm is journaled within a cylindrical sieve d and is provided with the spirally rising hub according to this invention. The material to be compressed'is charged in from the top by way of a hopper and is conveyed downwardly from the side of the small radius 1' of the hub by the helical band 0 which in this case completlellly is discharged at Figs. 6 and 7 show the invention applied to a clay purifier. The worm provided according to this invention with a helically rising hub 12 and helical band 0 is in this case rotated likewise within a cylindrical sieve d. The latter is attached to a cylindrical casing g which carries at the top a charging box h. Rotating in this box is a shaft 13 provided with agitating wings j for mixing the clay and cooperating with the mixing and conveying worm is in the caslng The same device may, without further modification, be employed also as a press for slicings, the mixing wings j being omitted for this purpose.

Fig. 8 shows a constructional form and a rotary pump for liquids of all kinds. but, more particularly, for liquids of a thick and pulpy consistency. In this case, as shown in the drawing, the worm is duplicated symmetrically so that one side is left-threaded and the other right-threaded. The liquid to be forced enters by way of the branch conduits m and in being simultaneously concentrated is conveyed to the central delivery conduit n. In this case the helical band, 0 fills the clear width of the jacket d as completely as possible.

Fig. 9 shows the constructional example of a disintegrating machine arranged particularly as stone crusher for the reduction of coarse materials of all kinds. The arrange ment of the apparatus is upright. The shaft a is rotated by some suitable driving gear in the direction of the arrow and is provided with the spirally rising hub. The helical band a wound around this hub is, in this case, not of a purely prismatical or triangular cross section, but, as shown, has each turn subdivided into two orseveral bands of triangular cross-section. As the shaft rotates in the direction of the arrow, the material charged in is conveyed downwardly by the threads 0 and owing to the spirally shaped hub is simultaneously pressed radially against the crushing jacket 0. The latter is, in this case, preferably provided with sharp edged helical ribs p.

The constructional forms above described for explanatory purposes are obviously destined solely to illustrate individual instances of the application of the invention The worm provided with a spirally rising 'hub may, for example, also be used in a filter press, fruit press and the like. Similar to a clay purifier it may also be employed as a clay press or as a mixing press or as a strand press for cement and other granular materials as well as for plastic masses. In the case of a strand press the sieve d shown in Fig. 6 would be replaced by a solid jacket and while the last section 4 of the worm boss would be lengthened, a closed jacket would be attached at the end provided with the usual conical mouthpiece enabling the mixed and compressed material to leave the press in the form of a strand and to be cut in a known manner into individualprismatical pieces.

In the examples shown the mantle or jacket has been assumed to be of cylindrical shape. It is, however, obvious that the conveying worm provided with a spirally rising hub according to this invention may rotate in a conical housing and, moreover, that'the helical band need not be continuous but may consist of individual sections or parts of' such a band. In all cases it is important that the hub carrying the helical band should be of the shape of a helix as shown in Fig. 2.

What I do claim as my invention and desire to secure by Letters Patent of the United States is: a

A screw conveyer comprising a shaft provided with a boss, the elements in the outer surface of which lie parallel to the axis of said shaft, said boss extending around and progressing along said shaft and increasing in radius from one end toward the other, and a helical band arranged on said boss.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

OTTOMAR OSKAR ERFURTH. Witnesses:

RICHARD DREYHAUPT, 'RUooLrH FRICKE. 

